System for transmitting ultrasonic energy through core samples

Abstract

A system for measuring ultrasonic (50 Khz-10 Mhz) velocity and attenuation in core samples employs transmitting and receiving transducers for generating and receiving ultrasonic energy in a core sample. The transducer and core sample are contained in a high pressure cell. The transducers are isolated from the high pressure of the cell by suitable housings, allowing the transducers to operate at ambient pressure.

What is claimed is: 
     
       1. A system for transmitting ultrasonic energy through a material sample comprising: (a) ultrasonic energy transducing means in contact with said material sample for transmitting ultrasonic energy into said sample and for receiving the energy after it has traveled through said sample,   (b) a pressure cell for housing said sample under a confining pressure simulating subterranean pressure conditions, and   (c) means for isolating said ultrasonic energy transducing means from the confining pressure condition on said cell such that said ultrasonic energy transducing means operates at ambient pressure conditions.   
     
     
       2. The system of claim 1 wherein said means for isolating said ultrasonic energy transducing means from said confining pressure comprises a housing adapted for completely enclosing said ultrasonic energy transducing means excepting only for the face of said ultrasonic energy transducing means which is in direct contact with said sample. 
     
     
       3. The system of claim 2 wherein said ultrasonic energy transducing means is slidably mounted within said housing, said housing is spaced apart from said sample, and said housing includes at least one spring-like member for forcing said ultrasonic energy transducing means into contact with said sample. 
     
     
       4. The system of claim 2 wherein said housing includes a passageway through which the fluid pressure within the sample can be selectively adjusted from a suitable fluid pressure supply independently of the confining pressure within said cell. 
     
     
       5. The system of claim 1 wherein said ultrasonic energy transducing means operates at ambient pressure within said housing while the sample is under a confining pressure up to 10,000 pounds per square inch. 
     
     
       6. The system of claim 1 wherein said ultrasonic energy transducing means operates alternately in the transmit and receive modes to transmit ultrasonic energy into said sample and to receive the energy upon its reflection from the interface provided by the opposite end of the sample. 
     
     
       7. The system of claim 1 wherein said ultrasonic energy transducing means comprises: (a) a first transducer in contact with a first end of said sample for transmitting ultrasonic energy into said sample,   (b) a second transducer in contact with a second end of said sample for receiving energy after it has travelled through said sample.   
     
     
       8. The system of claim 7 wherein said isolating means comprises: (a) a first housing adapted for completely enclosing said first transducer excepting only for the face of said first transducer which is in contact with said first end of said sample, and   (b) a second housing adapted for completely enclosing said second transducer excepting only for the face of said second transducer which is in contact with said second end of said sample.